As expected, the new budget projections from the Office of Management and Budget show an estimated deficit of $1.58 trillion in the current year (which ends on September 30).

In their coverage of the dueling budget releases, many members of the media are noting that this estimate is almost identical to the $1.59 trillion estimate released by the Congressional Budget Office. Thus, it may appear that OMB and CBO reached similar conclusions about this year’s deficit.

That is not correct.

OMB and CBO use different accounting for a growing part of the budget — the federal take-over of Fannie Mae and Freddie Mac. If you adjust for those accounting differences, an apples-to-apples comparison shows that OMB’s projection of a $1.58 trillion deficit should be compared to a CBO estimate of $1.41 trillion. (For details, see the table on p. 2 and the box on pp. 8-9 of CBO’s report.)

In other words, using identical accounting, CBO is projecting a deficit that is almost $200 billion less than projected by OMB.